Finding the Fourth Proportional to 1,016.90, 1,404.06 and 624.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,016.90 : 1,404.06 = 624.45 : x
2. Step 2: Convert to fraction form
   1,016.90/1,404.06 = 624.45/x
3. Step 3: Cross multiply
   1,016.90x = 1,404.06 × 624.45
4. Step 4: Simplify right side
   1,016.90x = 876,765.27
5. Step 5: Solve for x
   x = 876,765.27/1,016.90
6. Step 6: Final answer
   x = 862.20